Health & Lifestyles - Chapter 3

FIT & WELL: Core Concepts and Labs in Physical Fitness and Wellness

Introduction

  • Authors: Thomas D. Fahey, Paul M. Insel, Walton T. Roth, Claire E. Insel

  • Edition: Fourteenth Edition (2021)

  • Publisher: McGraw-Hill Education

  • Chapter Focus: Cardiorespiratory Endurance

Learning Objectives

  • Describe energy production for exercise.

  • List the major effects and benefits of cardiorespiratory endurance exercise.

  • Explain measurement and assessment of cardiorespiratory endurance.

  • Discuss FITT-VP components affecting cardiorespiratory endurance development.

  • Explain prevention and treatment of common exercise injuries.

Basic Physiology of Cardiorespiratory Endurance Exercise

  • Cardiorespiratory System: Circulates blood; consists of the heart, blood vessels, and respiratory system.

The Role of the Heart

  1. Structure: Fist-sized muscle with four chambers.

    • Pulmonary Circulation: Moves blood between heart and lungs (right side of heart).

    • Systemic Circulation: Moves blood from heart to the rest of the body (left side of heart).

  2. Blood Flow Pathway:

    • Oxygen-poor blood enters heart via venae cavae → fills right atrium.

    • Blood is pumped from right atrium to right ventricle → pulmonary artery → lungs (oxygen uptake, carbon dioxide removal).

    • Oxygen-rich blood returns via pulmonary veins to left atrium, then left ventricle → aorta → rest of body.

  3. Definitions:

    • Systole: Contraction phase of the heart.

    • Diastole: Relaxation phase of the heart.

    • Blood Pressure: Force exerted by blood on blood vessels. Typical values: 120/80 mmHg.

Blood Vessels

  • Types:

    • Veins: Carry blood to the heart.

    • Arteries: Carry blood away from the heart.

    • Capillaries: Small vessels facilitating blood distribution.

    • Coronary Arteries: Supply the heart muscle with oxygenated blood.

The Respiratory System

  • Definition: Comprises lungs, air passages, and muscles that facilitate oxygen supply and carbon dioxide removal.

  • Alveoli: Tiny air sacs where gas exchange occurs.

Body Functionality at Rest and Exercise

  • At Rest: 50-90 heartbeats/min, 12-20 breaths/min.

  • During Exercise:

    • Increased heart rate.

    • Deeper, faster breathing.

    • Increased stroke volume and cardiac output.

    • Enhanced blood supply to working muscles.

    • Increased systolic blood pressure; diastolic stays steady/slightly decreases.

Energy Production and Metabolism

  • Metabolism: Sum of chemical processes to maintain body functions.

  • Energy sources: carbohydrates, proteins, fats.

  • Glucose: Simple sugar for ATP production.

  • Glycogen: Stored glucose, major fuel source during intense exercise.

  • ATP (Adenosine Triphosphate):

    • Basic energy currency for cells.

    • Created through chemical reactions using stored fuels.

The Three Energy Systems

  1. Immediate (Explosive) Energy System:

    • Supplies energy through breakdown of ATP and creatine phosphate (CP).

  2. Nonoxidative (Anaerobic) Energy System:

    • Fuels energy through breakdown of glucose/glycogen.

    • Produces lactic acid when anaerobic metabolism occurs.

  3. Oxidative (Aerobic) Energy System:

    • Uses oxygen to metabolize glucose/glycogen/fats.

  • VO2max: Highest rate of oxygen consumption during maximum effort, measured in mL O2/min/kg.

Characteristics of Energy Systems (Table 3.1)

  • Immediate Energy System:

    • Duration: 0–10 seconds

    • Intensity: High

    • Fuel: ATP, CP

    • Oxygen: No

    • Example Activities: Weight lifting.

  • Nonoxidative Energy System:

    • Duration: 10 seconds to 2 minutes

    • Intensity: High

    • Fuel: Muscle stores of glucose/glycogen

    • Oxygen: No

    • Example Activities: 400-meter run.

  • Oxidative Energy System:

    • Duration: >2 minutes

    • Intensity: Low to moderately high

    • Fuel: Glycogen, glucose, fat, protein

    • Oxygen: Yes

    • Example Activities: 1,500-meter run, 30-minute walk.

Benefits of Cardiorespiratory Endurance Exercise

  1. Efficiency Improvement:

    • Better coping with physical challenges.

    • Lower risk for chronic diseases.

  2. Enhanced Heart Functioning:

    • Increased oxygen and nutrient supply to heart.

    • Improved cardiac contractions and blood volume.

    • Stabilized electrical activity, reducing cardiac arrest risk.

  3. Improvement in Cellular Metabolism:

    • Increased capillary number in muscles.

    • Enhanced oxygen and fuel utilization in cells.

    • Protection against free radical damage.

  4. Chronic Disease Risk Reduction:

    • Lowers cardiovascular disease, type 2 diabetes, and cancer risks.

    • Reduces acute inflammation post-workout.

Assessing Cardiorespiratory Fitness

  1. Tests:

    • 1-Mile Walk Test: Completion time and heart rate measured post-walk.

    • 3-Minute Step Test: Pulse return to baseline after stepping exercise.

    • 1.5-Mile Run/Walk Test: Speed assessed for VO2max.

    • Beep Test: Predicts VO2max based on pacing to audio beeps.

  2. Interpretation of Scores:

    • Field tests have 10-15% margin of error; best for progress tracking over time.